Refrigerant condenser and method of forming same



g- 4, 1942' L. w. ATCHISON 2,292,033

REFRIGERANT CONDENSER AND METHOD OF FORMING SAME Filed Aug. 1, 1941 'Fi .I. f2 2: 1

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lhvehborz Leonard W Atchison, by WW6. 244%,

His Attorney.

Patented Aug. 4, 1942 REFRIGERANT OF Leonard W. Atchison,

or to General Elect of New York Application August 3 7 Claims.

My invention relates to refrigerant condensers or similar heat exchangers and particularly to an air cooled condenser of the chimney type arranged to be mounted on the back of a household refrigerator.

It is an object of my invention to provide an improved heat exchanger or condenser of the chimney type for refrigerating machines.

Another object of my invention is to provide an improved method for constructing a condenser for a refrigerating machine.

Further objects and advantages of my invention will become apparent as the following description proceeds, and the features of novelty which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention reference may be had to the accompanying drawing in which Fig. l is a side elevation view partly in section of a household refrigerator including a refrigerating machine provided with a condenser embodying my invention; Fig. 2 is a front perspective view of the condenser shown in Fig. 1; Fig. 3 is an enlarged sectional view on the line 3--3 of Fig. 2; and Fig. 4 is a perspective view of a portion of the condenser shown in Fig. 2 during one step of its manufacture.

Briefly, the household refrigerator shown in the drawing comprises a thermally insulated cabi- ESEE AND METHOD some No. 404,964

(or. ire-no net provided with a mechanical refrigerating machine of the compression type which includes an. air cooled condenser mounted on the basis wail of the cabinet. The condenser comprises a hollow chimney hire sheet metal structure of clon gated suhstantiaiiy rectangular cross section. The condenser is constructed by providing a cor rugation along one edge of a strip or" sheet metal and then winding the strip hclically to form cylindrical structure, the edges of strip overlapping so that the corrugation. cooperates with the edge it overlaps to form. a helical. refrigerant passageway or conduit. The edges of the strip are welded or otherwise suitably bonded together along the edges of the corrugation order to seal the refrigerant conduitl The cylindrical structure is "attened provide a duct or flue of the desir a relatively thin. fiat cross section suitable con meet on for the at .iahdrawai of re Reici new to drawing, the refrigerating inachiuie showuin Fig. 1 comprises a therma'iiy insulated (":abhiet it provided with a door ii and evaporator l3 and a machinery compartment I4 below the food compartment and in which is located a hermetically sealed motor compressor unit l5. An upright chimney type condenser [6 having a helical refrigerant conduit I1 is mounted at the back of the cabinet so that air may circulate therethrough and over the outside thereof, air from the machinery compartment circulating upwardly between the back of the cabinet and the front wall of the condenser. Hot compressed refrigerant is delivered from the motor compressor unit [5 through a connection I8 which extends upwardly through the chimney of the condenser i6 and discharges the refrigerant to condenser conduit I! at the top thereof. The refrigerant is cooled by the circulation of air over the condenser and is liquefied and flows to the bottom of the condenser and thence through a liquid line I9 to a liquid receiver or float valve chamber 20 mounted in the upper portion of the cabinet to. Refrigerant flows from the chamber 20 under the control of the float therein and enters the evaporator 13 through a connection 21. Liquid refrigerant is vaporized in the evaporator and the gaseous refrigerant collects in a header 22 from which it is withdrawn through a suction line 23 and is returned to the compressor in the casing iii.

As shown in Fig. 2 the condenser l6 comprises a sheet metal strip 2 1 wound helically with its edges overlapping as shown in Fig. 3. The top overlapping edge of the strip is provided with a corrugation which forms the conduit ii and the edges of the strip welded, brazed, or otherwise suitably bonded together along both edges of the corrugation iii so that the concave side of the corrugation faces the adjacent edge of the next turn of the helically Wound strip and forms a continuous helical conduit. An inlet connection comprising the end of the conduit i8 is connected to the conduit ill the top thereof and an outlet connection comprising the end of the conduit to is secured in communication with the bottom end of the conduit When constructing the chimney type condense: it I have found it preferable to form the corrugation along one edge of a strip of sheet metal, then to wind the strip in helical form with. the concave side of "the corrugation overlapping the adjacent turn of the strip as shown a, thereby forming a substantially cylindrical struc" ture. The strip is welded together aiong both. edges of the corrugation ill to form a rigid structure and to seal the corrugation and provide having a food compartment 92 cooled by an a continuous helical refrigerant conduit. After a sufllcient length of the strip has been wound in cylindrical form, the structure is flattened to provide the condenser of substantially rectangular cross section as indicated in Figs. 1 and 2, and the strip at the ends is then cut oil substantially at right angles to the longitudinal axis of the condenser as indicated at the bottom of Fig. 2 where the portion to beremoved is shown in the dot and dash outline. The connections l8 and H are thereafter silver soldered or otherwise suitably secured and sealed in position at the ends of conduit. ll. The condenser structure is then mounted on the rear of the cabinet ill by suitable brackets at and 2B.

In some cases it may be found desirable to cut off or trim the ends of the strip 24 at an angle to remove the end portions at the top and bottom corresponding to the bottom portion shown in the dotted outline in Fig. 2, so that when the strip has been wound helically and welded at the edges of the strip, the ends are already formed so that they lie in the desired plane perpendicular to the longitudinal axis of the cylinder.

From the foregoing it is readily apparent that I have provided a condenser or heat exchanger of simplified construction which requires a minimum amount of material and which provides a rigid structure providing an extended surface for the rapid exchange of heat with the surround ing air that circulates over the condenser by natural draft.

While I have described a particular embodimerit of my invention in connection with household refrigerator, other applications will he apparent to those skilled in the art. i do not, therefore, desire my invention to be limited to the particular construction shown and described, and I intend in the accompanying claims cover all modifications within the spirit scope of my invention.

What 1 claim as new and desire to secure by Letters Patent of the United States is:

l. A heat exchange element for a refrigerating machine comprising a helically wound. strip of sheet metal having its adjacent edges over lapping, at least one oi said overlapping edges being formed with an elongated corrugation proriding a passageway for fluid between said ad--= iacent edges and extending helically about said element, said edges. being bonded. together on both sides of said corrugation to seal said passageway and to provide a rigid structure.

2. A chimney type condenser for refrigeratlng machine comprising a helically wound stri of sheet metal having its adjacent edges overlapping, at least one of said overlapping edges being formed with an elongated corrugation providing a passageway for fluid between said. ad. iecent edges and extending helicaily about said condenser, said edges being bonded together along both edges of said corrugation to seal said passageway and to provide a rigid structure forming a chimney or" relatively thin cross section and being adapted to be mounted on. a refrigerator cabinet and to induce a natural cir culation of air over the surface of said condenser.

3. The method of manufacturing from a metal strip a condenser for a refrigerating machine which comprises, forming a corrugation along one edge oi the strip, winding the strip helically in a substantially cylindrical form with the concave side of said corrugation overlapping the adjacent portion of the other edge of the strip, and welding the edges of the strip together along both edges of said corrugation to form a continuous helical passageway for fluid.

4. The method of manufacturing from a metal strip a condenser for a refrigerating machine which comprises, forming a corrugation along one edge of the strip, winding the strip helically into a structure of substantially cylindrical form with the concave side of said corrugation overlapping the adjacent portion of the other edge of the strip, welding the edges of the strip together along both edges of said corrugation to form a continuous helical passageway for fiuid and flattening said structure to provide a duct or flue of substantially rectangular cross section.

5. The method of manufacturing from a metal.

strip a condenser for a refrigerating machine which comprises, forming a corrugation along one edge of the strip, winding the strip helically into a structure of substantially cylindrical form with the concave side of said corrugation overlapping the adjacent portion of the other edge of the strip, welding the edges of the strip together along both edges of said corrugation to form a continuous helical conduit, and as a step in said method after the formation of said structure cutting off the ends of said structure in a plane substantially at right angles to the axis thereof attaching fittings to said conduit for the admission and discharge of refrigerant. 6. The method of manufacturing from metal strip a condenser for a refrigerating machine which comp ises, cutting the strip to a prede termined length and cutting the predetermined length of the strip adjacent its ends to predeter-= nn'ne the shape of the ends of the condenser, iormhig a corrugation along one edge or the strip, winding the strip heiically into a structure substantially cylindrical form with the concave side of said corrugation overlapping the adjacent portion of the other edge of the strip, welding the edges of the strip together along both edges of said corrugation to form a com tinuous helical. conduit, deforming the cylindrical structure to provide the desired shape of cross section of the condenser, and attaching fittings to the ends of said conduit for the admission and discharge of refrigerant.

l. A. chimney type condenser for a reirigerating machine comprising a helically wound strip of sheet metal having its adjacent edges over lapping, at least one of said overlapping edges being formed within an elongated corrugation providing passageway for fluid between said adjacent edges and extending helically about said condenser, said edges being welded together along both edges of said. corr gation to se aid passageway and to provir. ture forming a chimney of re til/61:] f e cross section being adapted be mounted on a 

